GNUnet  0.10.x
Data Structures | Macros | Functions
nat_api_stun.c File Reference

This code provides some support for doing STUN transactions. More...

#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_resolver_service.h"
#include "gnunet_nat_service.h"
#include "nat_stun.h"
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Data Structures

struct  GNUNET_NAT_STUN_Handle
 Handle to a request given to the resolver. More...
 

Macros

#define LOG(kind, ...)   GNUNET_log_from(kind, "stun", __VA_ARGS__)
 
#define TIMEOUT   GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 15)
 

Functions

static int encode_message (enum StunClasses msg_class, enum StunMethods method)
 Encode a class and method to a compatible STUN format. More...
 
static void generate_request_id (struct stun_header *req)
 Fill the stun_header with a random request_id. More...
 
static void stun_dns_callback (void *cls, const struct sockaddr *addr, socklen_t addrlen)
 Try to establish a connection given the specified address. More...
 
struct GNUNET_NAT_STUN_HandleGNUNET_NAT_stun_make_request (const char *server, uint16_t port, struct GNUNET_NETWORK_Handle *sock, GNUNET_NAT_TestCallback cb, void *cb_cls)
 Make Generic STUN request. More...
 
void GNUNET_NAT_stun_make_request_cancel (struct GNUNET_NAT_STUN_Handle *rh)
 Cancel active STUN request. More...
 

Detailed Description

This code provides some support for doing STUN transactions.

We send simplest possible packet ia REQUEST with BIND to a STUN server.

All STUN packets start with a simple header made of a type, length (excluding the header) and a 16-byte random transaction id. Following the header we may have zero or more attributes, each structured as a type, length and a value (whose format depends on the type, but often contains addresses). Of course all fields are in network format.

This code was based on ministun.c.

Functions for STUN functionality

Author
Bruno Souza Cabral

Definition in file nat_api_stun.c.

Macro Definition Documentation

◆ LOG

#define LOG (   kind,
  ... 
)    GNUNET_log_from(kind, "stun", __VA_ARGS__)

Definition at line 46 of file nat_api_stun.c.

Referenced by stun_dns_callback().

◆ TIMEOUT

Definition at line 48 of file nat_api_stun.c.

Referenced by GNUNET_NAT_stun_make_request().

Function Documentation

◆ encode_message()

static int encode_message ( enum StunClasses  msg_class,
enum StunMethods  method 
)
static

Encode a class and method to a compatible STUN format.

Parameters
msg_classclass to be converted
methodmethod to be converted
Returns
message in a STUN compatible format

Definition at line 102 of file nat_api_stun.c.

Referenced by stun_dns_callback().

104 {
105  return ((msg_class & 1) << 4) | ((msg_class & 2) << 7) |
106  (method & 0x000f) | ((method & 0x0070) << 1) | ((method & 0x0f800) << 2);
107 }
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◆ generate_request_id()

static void generate_request_id ( struct stun_header req)
static

Fill the stun_header with a random request_id.

Parameters
req,stunheader to be filled

Definition at line 116 of file nat_api_stun.c.

References GNUNET_CRYPTO_QUALITY_NONCE, GNUNET_CRYPTO_random_u32(), stun_trans_id::id, stun_header::id, stun_header::magic, and STUN_MAGIC_COOKIE.

Referenced by stun_dns_callback().

117 {
118  req->magic = htonl(STUN_MAGIC_COOKIE);
119  for (unsigned int x = 0; x < 3; x++)
121  UINT32_MAX);
122 }
uint32_t GNUNET_CRYPTO_random_u32(enum GNUNET_CRYPTO_Quality mode, uint32_t i)
Produce a random value.
stun_trans_id id
Definition: nat_stun.h:45
Randomness for IVs etc.
#define STUN_MAGIC_COOKIE
Definition: nat_stun.h:34
uint32_t magic
Definition: nat_stun.h:44
uint32_t id[3]
Definition: nat_stun.h:37
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◆ stun_dns_callback()

static void stun_dns_callback ( void *  cls,
const struct sockaddr *  addr,
socklen_t  addrlen 
)
static

Try to establish a connection given the specified address.

Parameters
clsour struct GNUNET_NAT_STUN_Handle *
addraddress to try, NULL for "last call"
addrlenlength of addr

Definition at line 133 of file nat_api_stun.c.

References GNUNET_NAT_STUN_Handle::cb, GNUNET_NAT_STUN_Handle::cb_cls, GNUNET_NAT_STUN_Handle::dns_active, GNUNET_NAT_STUN_Handle::dns_success, encode_message(), generate_request_id(), GNUNET_ERROR_TYPE_ERROR, GNUNET_ERROR_TYPE_INFO, GNUNET_log_strerror, GNUNET_NAT_ERROR_INTERNAL_NETWORK_ERROR, GNUNET_NAT_ERROR_NOT_ONLINE, GNUNET_NAT_ERROR_SUCCESS, GNUNET_NAT_stun_make_request_cancel(), GNUNET_NETWORK_socket_sendto(), GNUNET_NO, GNUNET_SYSERR, GNUNET_YES, LOG, stun_header::msglen, stun_header::msgtype, GNUNET_NAT_STUN_Handle::sock, STUN_BINDING, GNUNET_NAT_STUN_Handle::stun_port, STUN_REQUEST, and GNUNET_NAT_STUN_Handle::stun_server.

Referenced by GNUNET_NAT_stun_make_request().

136 {
137  struct GNUNET_NAT_STUN_Handle *rh = cls;
138  struct stun_header req;
139  struct sockaddr_in server;
140 
141  if (NULL == addr)
142  {
143  rh->dns_active = NULL;
144  if (GNUNET_NO == rh->dns_success)
145  {
147  "Error resolving host %s\n",
148  rh->stun_server);
149  rh->cb(rh->cb_cls,
151  }
152  else if (GNUNET_SYSERR == rh->dns_success)
153  {
154  rh->cb(rh->cb_cls,
156  }
157  else
158  {
159  rh->cb(rh->cb_cls,
161  }
163  return;
164  }
165 
166  rh->dns_success = GNUNET_YES;
167  memset(&server, 0, sizeof(server));
168  server.sin_family = AF_INET;
169  server.sin_addr = ((struct sockaddr_in *)addr)->sin_addr;
170  server.sin_port = htons(rh->stun_port);
171 #if HAVE_SOCKADDR_IN_SIN_LEN
172  server.sin_len = (u_char)sizeof(struct sockaddr_in);
173 #endif
174 
175  /* Craft the simplest possible STUN packet. A request binding */
176  generate_request_id(&req);
177  req.msglen = htons(0);
178  req.msgtype = htons(encode_message(STUN_REQUEST,
179  STUN_BINDING));
180 
181  /* Send the packet */
182  if (-1 ==
184  &req,
185  sizeof(req),
186  (const struct sockaddr *)&server,
187  sizeof(server)))
188  {
190  "sendto");
192  return;
193  }
194 }
detected that we are offline
void GNUNET_NAT_stun_make_request_cancel(struct GNUNET_NAT_STUN_Handle *rh)
Cancel active STUN request.
Definition: nat_api_stun.c:245
void * cb_cls
Closure for cb.
Definition: nat_api_stun.c:80
Handle to a request given to the resolver.
Definition: nat_api_stun.c:56
#define GNUNET_NO
Definition: gnunet_common.h:78
#define GNUNET_log_strerror(level, cmd)
Log an error message at log-level &#39;level&#39; that indicates a failure of the command &#39;cmd&#39; with the mess...
#define LOG(kind,...)
Definition: nat_api_stun.c:46
ssize_t GNUNET_NETWORK_socket_sendto(const struct GNUNET_NETWORK_Handle *desc, const void *message, size_t length, const struct sockaddr *dest_addr, socklen_t dest_len)
Send data to a particular destination (always non-blocking).
Definition: network.c:838
struct GNUNET_NETWORK_Handle * sock
Handle to the listen socket.
Definition: nat_api_stun.c:65
Failure in network subsystem, check permissions.
char * stun_server
Stun server address.
Definition: nat_api_stun.c:70
#define GNUNET_SYSERR
Definition: gnunet_common.h:76
GNUNET_NAT_TestCallback cb
Function to call when a error occours.
Definition: nat_api_stun.c:75
static int encode_message(enum StunClasses msg_class, enum StunMethods method)
Encode a class and method to a compatible STUN format.
Definition: nat_api_stun.c:102
uint16_t stun_port
STUN port.
Definition: nat_api_stun.c:90
int dns_success
Do we got a DNS resolution successfully?
Definition: nat_api_stun.c:85
#define GNUNET_YES
Definition: gnunet_common.h:77
static void generate_request_id(struct stun_header *req)
Fill the stun_header with a random request_id.
Definition: nat_api_stun.c:116
struct GNUNET_RESOLVER_RequestHandle * dns_active
Handle to a pending DNS lookup request.
Definition: nat_api_stun.c:60
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